It is unclear as yet which carriers are featured on the service, or if they belong to particular groupings (Lufthansa is part of Star Alliance), but they are said to be "large and medium-sized airlines".

The free system works by taking control of a passenger's check-in requirements from the AirlineCheckins website.

Members forward or register their booking confirmation details on the site, then it automatically checks the passenger in as soon the host carrier's system allows it ("usually in the very first minute", the site says).

The system also includes a preferences element, so passengers can notify the service if they like a seat towards the front or rear of an aircraft, aisle or window seat, etc.

AirlineCheckins will forward the passenger's boarding pass once the check-in is completed, by email, SMS or via another channel.

LIH says:

"The online check-in process is identical to the face-to-face discussion at the airline’s check-in desk at the airport, but it has the benefit of allowing you to go directly to security when you arrive at the airport, then head straight to your gate, where you scan your previously issued boarding pass at the appropriate checkpoint or show your pass to the relevant employee."